• The U-MAKER Project: Using 3D printed models to help the understanding of geological structures and raising decision-makers’ awareness of geological issues, Dominique Frizon de Lamotte et al., CY Cergy Paris Université
  • Quantum transport in twisted bilayer graphene, Guy Trambly de Laissardière et al., CY Cergy Paris Université
  • Topological states at the InBi(100) surface, Karol Hricovini et al., CY Cergy Paris Université, France
  • Development of technology for spatial three-dimensional liquid chromatography, J. De Vos et al., Vrije Universiteit Brussel
  • Laboratoire de Physico-chimie des Polymères et des Interfaces, O. Fichet, CY Cergy Paris Université, France
  • Adaptive Thermal Control of Satellites by ElectroActive Polymeric Coating, Pierre-Henri Aubert, G. Petroffe et al., CY Cergy Paris Université
  • Ionic Electroactive Polymers: soft actuators and soft sensors, C. Plesse et al., CY Cergy Paris Université
  • Cationic polymers: mimicking antimicrobial peptides to combat bacterial infections, R. García Maseta et al., University of Warwick.
  • Comportement des éléments de structures, E. Ghorbel and George Wardeh, CY Cergy Paris Université
  • Experimental investigation on physico-mechanical properties of natural building stones exposed to fire, M. Vigroux et al., CY Cergy Paris Université
  • Plasma Swing, Mechanichally self-adjusting plasma, S.Dahle, University of Ljubljana

The U-MAKER Project: Using 3D printed models to help the understanding of geological structures and raising decision-makers’ awareness of geological issues

Dominique Frizon de Lamotte, Pascale Leturmy, Pauline Souloumiac and Adrien Frizon de Lamotte

U-Maker/GEC- CY Cergy Paris Université

U-MAKER is a project but also an open-lab associated to the Research Team: Geosciences and Environment Gergy (GEC). We are developing projects in the field of Earth science education and scientific mediation of industrial (or other) projects.

Geology is a scientific discipline where a 3D view is important – even essential. When starting to learn geology, as a first exercise students should be able to gain a 3D vision of geological maps, which like all maps are 2D objects, and interpret them. Many people have an objective difficulty in “seeing in 3D”, that is, in achieving a mental representation of a dimension, which is not shown.

This is indeed important for Earth sciences students but also for anyone facing a problem with a geological dimension: establishment of a quarry, a storage site, a geothermal project, protection of a water capture site… Geotourism is another aspect where 3D models can bring a lot.

For the students, we propose a wide range of objects, which anyone can use or make in line with an educational approach that combines digital creation and object manipulation. In fact, our computer-designed prototypes are saved in a format from which they can be printed in 3D. Three types of objects are presented:

  1. Models, which help to see things in 3D and thus understand particular structures;
  2. Models where the third dimension offers an approach to successive geometries (kinematics) during the formation of particular geological structures;
  3. Models that provide the opportunity to move different parts relative to each other to generate structures like faults.
  4. Models illustrating field trips and allowing students to locate in the field.

For other people and in particular for anyone needing to explain a geological question to people with little knowledge and/or information, we are able to propose printed models of natural examples in different geological context.

Topological states at the InBi(100) surface

Karol Hricovini (1), Ján Minár (2), Christine Richter (1), Olivier Heckmann (1), Jean-Michel Mariot (3), Janusz Sadowski (4), Jürgen Braun (5), Hubert Ebert (5), Jonathan Denlinger (6), Ivana Vobornik (7), Jun Fujiik (7), Pavol Šutta (2), Martin Gmitra (8) and and Laurent Nicolaï (2)

(1) Laboratoire de Physique des Matériaux et des Surfaces, CY Cergy Paris Université, France;    
(2) University of West-Bohemia, Plzeň, Czech Republic  
(3) Laboratoire de Chimie Physique-Matière et Rayonnement, Sorbonne Université, Paris, France    
(4) Linnaeus University, Kalmar, Sweden    
(5) Ludwig-Maximilians-Universität München, Germany    
(6)Advanced Light Source, Berkeley, United States of America    
(7) Elettra Synchrotrone Trieste, Italy    
(8) Department of Theoretical Physics and Astrophysics, P. J. Šafárik University in Košice, Slovakia 

The ongoing research in topologically protected electronic states is driven not only by the obvious interest from a fundamental perspective but is also fuelled by the promising use of these non-trivial states in energy technologies such as the field of spintronics. It is therefore important to find new materials exhibiting these compelling topological features. InBi has been known for many decades as a semi-metal in which Spin-Orbit Coupling plays an important role. SOC plays a key role for emergence of novel topological states.

We present a thorough analysis of InBi, grown on InAs(111)-A surface, both, experimental by Angular-Resolved Photoemission Spectroscopy measurements and theoretical by fully-relativistic ab-initio electronic band calculations. We found existence of topologically non-trivial metallic surface states due to formed Bi bilayer with fundamental role of Bi within these electronic states. Moreover, InBi appears to be a topological crystalline insulator whose Dirac cones at the (001) surface are pinned at high-symmetry points. Consequently, as they are also protected by time-reversal symmetry, they can survive even if the in-plane mirror symmetry is broken at the surface.

Development of technology for spatial three-dimensional liquid chromatography

Jelle De Vos, Thomas Themelis, Ali Amini, Sebastiaan Eeltink

Vrije Universiteit Brussel, Department of Chemical Engineering, Pleinlaan 2, Brussels, Belgium

High-performance liquid chromatography (HPLC) has emerged as a dominant separation technique in the field of analytical chemistry and is widely applied in many areas, including life-science research, clinical diagnostics, and the (bio)pharmaceutical sector. For the analysis of samples used in biomarker discovery studies, which are typically characterized by a large sample complexity (often containing over 1,000,000 compounds) and broad dynamic range, the current state-of-the-art HPLC technology does not allow to fully resolve the analytes. Column-based multidimensional LC approaches, i.e., by coupling columns with complementary (orthogonal) separation mechanisms, have been developed to improve the separation performance. In this separation platform, where the fractions originating from multiple columns are sequentially analyzed, a single analysis takes a long time to complete. This makes the technology intrinsically unsuitable for high-throughput screening.

To advance the separation performance, and to overcome this bottleneck of sequential runs, the development of a microfluidic separation device for spatial 3D-LC was explored. In spatial 3D-LC chromatography components are separated inside the microchannels of the device with each peak being characterized by its X, Y, and Z coordinates in the separation body. We investigated different design aspects of a microfluidic device for comprehensive spatial 3D-LC, including flow distributor design and channel layout. During the different developments in X-, Y-, and Z-direction, the analytes and therefore the flow should not convolute in other dimensions. To this end, we developed active flow confinement technology, which also allows to modulate the mobile-phase composition between the 1st and 2nd dimension development. To allow for automated process operation, mechanisms applying advanced robotics have been successfully integrated on-chip. Furthermore, approaches to integrate functionalized monolithic stationary phases at pre-defined locations in microfluidic device have been realized, which are essential to realize a spatial 3D-LC separation of complex samples.

Ionic Electroactive Polymers : soft actuators and soft sensors

Cedric Plesse , Giao Nguyen , Cedric Vancaeyzeele , Frederic Vidal

CY Cergy Paris Université, LPPI, Chemistry dpt, 95000 CERGY, FRANCE

Ionic ElectroActive Polymers (EAPs) are smart materials which respond to an electrical stimulus by undergoing volume variation due to ion motions. Since the first works on these materials in the early 90’s, numerous concepts have been described and have stimulated the imagination of chemists, physicists, biologists and mechanical engineers since they make possible the development of biomimetic soft actuators and soft sensors, precursors of so-called artificial muscles, with numerous potential applications in soft robotics, microelectromechanical systems, biomedical devices or smart textiles. Electronic conducting polymers (ECPs) belongs to the family of ionic EAPs and present numerous advantages such as being lightweight, soft, biocompatible and activated by low voltage (<2V). Their actuation principle relies on the ECP volume variation induced by ion exclusion/expulsion when submitted to a redox process in the presence of an electrolyte. Combining ECP electrodes and ionic conducting membranes allows developing trilayer devices able to operate in open-air and to (i) convert electrochemical stimulation into mechanical work (actuator) or (ii) to detect and quantify mechanical stimulation through output electrical signal (sensor).

The performances of such devices are mainly determined by the interdependent properties of the two partners: ECP electrodes (electronic conductivity and electroactivty) and ionic conducting membranes (ionic conductivity and mechanical robustness). We described here the work developed in LPPI (CY) on versatile electroactive devices, able to contract, expand, bend or sense by the synthesis of conducting Interpenetrating Polymer Network (IPN) architecture allowing to combine and tune these properties. According to this strategy, it has been possible to elaborate efficient electroactive materials but also to miniaturize them with classical microsystem processes allowing the development of soft (micro-)actuators and sensors. Finally, elaborating these materials with various shapes allowed the development of innovative biomedical applications such as electroactive catheter precursors with electrocontrollable bending or 3D porous electroactive scaffolds (electrospun fiber mats or polyHIPEs) with electrotunable porosity for cell mechanotransduction and tissue engineering.

Experimental investigation on physico-mechanical properties of natural building stones exposed to fire ​

Martin Vigroux (1), Javad Eslami (1), Anne-Lise Beaucour (1), Albert Noumowé (1) Anne Bourgès (2)

(1)  L2MGC, CY Cergy Paris Université
(2) LRMH, Ministère de la Culture et de la Communication, France

Fire appears as one of the main causes of built heritage weathering because it can generate irreversible damage with long-lasting effects, in a very short period of time. A well-known example for that is the recent fire that devastated Paris‘ world-famous NotreDame Cathedral on April 15th 2019.

This study focuses on the the study of the high temperature behaviour of various natural stones, used as building materials in the built heritage. Firstly, experimental measurements under high temperature allowed the identification of physico-chemical phenomena occurring during heating and cooling. Thus, the influence of mineralogy on the thermo-chemical stability of limestones and sandstone has been discussed. In addition, thermal deformation measurements up to 1050 °C have highlighted the role of certain petrophysical parameters on the mechanical behaviour of these stones at high temperatures. The evolution of thermal properties during heating has been determined. In addition, the evolution of residual properties (compressive strength, tensile strength, dynamic modulus of elasticity, total porosity, water capillary coefficient) of these stones after heating-cooling cycles up to 800 °C was experimentally determined. Microscopic observations, coupled with mercury porosimetry analyses, allowed the assessment of the porous network modification. The results of this study, obtained using different experimental methods, contribute to the diagnosis of stone-heritage structures that have suffered a fire. On the one hand, the consequences of the post-fire structural capacity have been established and, on the other hand, the consequences on its durability facing various environmental attacks have been analyzed.